Electric furnace



2 Sheets-Sheet l.

'{NOMOM E F PRICE ELECTRIC FURNACE.

Patented June 8,1897.

THE nonnls PETERS c0 wo'racrwa. wAsumcmu. nv c (No Model.) 2Sheets-Sheet 2. E. 1?. PRICE.

ELECTRIC FURNACE.

No. 583,936. Patented June 8,1897.

UNITED STATES PATENT FFICE.

EDGAR F. PRICE, OF NIAGARA FALLS, NEIV YORK, ASSIGNOR, BY MESNEASSIGNMENTS, TO THE ELEOTRO GAS COMPANY, OF IVEST VIRGINIA.

ELECTRIC FURNACE.

SPECIFICATION forming part of Letters Patent No. 583,936, dated June 8,1897.

Applicati n filed September 23, 1896. Serial No. 606,693. (No model.)

To all whom it may concern.-

Be it known that I, EDGAR F. PRIcE, a citizen of the United States,residing at Niagara Falls, in the county of Niagara and State of NewYork, have invented an Improvement in Electric Furnaces, of which thefollowing; is a specification.

The object of this invention is especially to provide an electricfurnace adapted to the fusing of materials, such as lime and carbon inthe manufacture of carbid of calcium, but the same may be availed of inthe electrical treatment of other substances. I make use of a hearthforming one electrode, and over :5 the same are carbon electrodes, andthe material is supplied through a hopper which is made with wallspreferably double for allowing water to circulate through the same forkeeping it cool, and the electrodes are constructed in a peculiarmanner, as hereinafter designated, and mechanism is provided foragitating or stirring the materials near the electric arc, and theatmosphere is excluded during the operation, and the materials which maybe carried off with the vapors generated pass up through an escape-fluewith alternating deflectors, upon which the solid materials accumulate,and spring-doors are provided for the discharge of these materials intoa receptacle. I also adjust the inclination of the hearth in such amanner that the materials that are melted in the electric arc flowtoward and over the delivery end into a receivingchamber and are takenfrom thence periodic- 3 5 ally through a suitable opening provided witha removable air-tight door.

In the drawings, Figure 1 is a longitudinal vertical section. Fig. 2 isa cross-section. Fig. 3 represents the upper end of one of the carbonrack-bars and the device for regulating the position of the carbonsautomatically. Fig. 4 is a plan view of the carbon-clamp; and Fig. 5shows, in larger size, the cap connecting the carbon and the conductor.

5 The furnace is constructed with side walls A and a front wall B, andthe escape-flue G is preferably in the rear, and these are to be of anysuitable size and character, and behind the front wall B is a chamber 4for receiving the finished product, and there is a wall atD thatsupports the lower front end of the hearth E, which hearth is preferablymade with a cast-iron bed-plate 5 at the sides and below the hearth E,which is advantageously of carbon, and the inclination of this hearthcan be varied by the adjusting screw F, passing through a nut F, suchscrew being below the back end of the hearth, and the front and lowerend of the hearth rests upon a roller 6 to lessen friction as the partsmay be adj usted. One pole of the electric generator is connected withthis hearth E in any suitable manner. I have represented a bracket 7bolted upon the bed platc 5, and to this the conductor G is clamped, andthis conductor should be insulated and of the proper size in proportionto the current made use of in the electric furnace.

Between the walls of the furnace there is a hopper H, madeadvantageously of molded 7o fire-clay or of boiler-iron, with doublewalls, through which water is caused to circulate.

I have shown the hopper made of boiler-iron, the water entering througha supply-pipe 8, the water passing away through the pipe 0, and thesubstances to be acted uponsuch, for instance, as carbon and lime intheir proper conditio11are supplied into the hopper and pass down aroundthe electrodes. For convenience in handling, thehopper may be made insections, each section having an independent supply-pipe and anindependent wastewater pipe.

The carbon electrodes I are to be of suitable size and more or lessnumerous. I have represented six of these carbon electrodes occupying asubstantially vertical position above the hearth E and passing downthrough the opening in the hopper II, there being a sufficient spacebetween the sides of the hopper and the carbon electrodes for thematerial to pass down freely; and it is to be observed that the surfacesof the hopper II are curved and are wider apart at the lower edges thanthey are in the middle portions of the hopper, so that the materials inthe hopper will drop down progressively as the operations go on.

In the cross-section, Fig. 2, it will be ob served that there are spacesbelow the hopper H and between the same and the side wall, which spacesform flues 10 for the passage of any gases that may be generated as theyare led away through these flues 10 to the escape-flue (l, and thisescape-flue is advantageously vertical and provided with inclineddeflectors 11, placed alternately, as represented, the lower edge of onedeflector being connected to the vertical partition 12, and there is aspace bet-ween such partition and the next deflector above, so that thegases and any solid materials that may pass away with such gases travelin a zigzag direction, and the solid materials will drop upon thedeflectors and accumulate adjacent to the vertical partition, and at 13doors or flaps are provided w llOll open by the pressure of materialsthat may accumulate upon the deflector, so as to allow such materials topass down the flue 14 to a receptacle 15 at the bottom. of the chimney.These doors or flues 13 should be closed either by weights or springs assoon as the material has opened such doors and discharged down the flue1%. By this arrangement the atmosphere is excluded from the furnace, butthe gaseous products are allowed to pass away progressively through thechimney or escape-flue.

At the delivery end of the hearth E materials that have been fused orotherwise acted upon by the heat pass into the chamber it, and there aredoors K that close openings in the walls of the furnace, and by theremoval of one or more of these doors access is given for taking thecarbid of calcium or other material out of the chamber 4, and thesedoors should be provided with cross-bars and screws or latches forholding such doors tightly closed and excluding the atmosphere. It willbe noticed that the carbon electrode which is over the delivery end ofthe hearth is closely adjacent to the hopper ll, so that the materialsin the hopper do not pass down between such electrode and the hopper atthe delivery end of the furnace. llenee there is little or no risk ofmaterial escaping into the chamber 4 until properly acted upon by theelectric current.

I find it advantageous to make use of stirrers L within the fines l0 andbelow the hopper. These stirrers L are to be moved backward and forwardat the proper periods of time, so as to prevent the material acted uponbecoming clogged or obstructed in its descent to the hearth. I prefer toconnect these stirrers to an endless chain Ill, that passes aroundpulleys N, and one of these pulleys should have sprocket-wheelprojections to act upon the chain, and the shaft and pulley should beconnected together, the shaft passing up through the wall of the furnaceand receiving at its upper end a hand-wheel or other device by which theparts can be actuated first in one direction and then in the other tomove the chain and carry the stirrers backward and forward beneath thehopper and at the sides of the carbon electrodes.

Difficulty has heretofore been experienced in electric furnaces in soconnecting the cenductors to the carbon electrodes that there will belittle or no resistance at the point of contact between the carbon andthe metal. To insure extent and intimacy of contact between the carbonand the metal, Iform in the upper end of the carbon a hole and tap thesame with a screw-thread and screw into the same a plug 0 of copper orsimilar material, and the metal cap (Z is screwed upon the upper end ofthis plug, and the lower end of the cap is thereby pressed into intimatecontact with the upper end of the carbon, and in the cap d is a lateralnotch for receiving the copper bar e, the head of the bar coming into arecess in the cap, and the clamp 1' around the copper bar and at the topof the metal cap serves to hold the copper bar firmly into contact withthe metal cap. By this arrangement the copper conductor is .lirmlyconnected with the carbon electrode, and the parts can be easilydisconnected from an electrode that may have become too short andconnected to a new carbon, so as to be inserted into the furnace, andthese copper bars 0 are guided by cross-bars f above the wall of thefurnace, and these cross-bars should be insulated, so as to preventground-currents, and the electrodes pass down progressively as they areconsumed, and I provide automatic means, as next described, forregulating the position of these carbon electrodes according to thestrength of the current that may be passing between the end of suchelectrode and the carbon hearth.

The current is supplied to the copper bar c through a conductor 7L,which is clamped firmly to the bar 6, and above this bar is a rack 02.,which is advantageously insulated from the cepperbar e, and there is apinion 0 that engages this rack, and one or more friction-rolls p areprovided behind the rack 91.. The pinion 0 and the gear-wheel 17 arepermanently connected; but they are loose on the shaft 16, and the pawlsl8 and 10 are connected in reverse positions to a vibrating frame 20,and there is a segment 21, adapted to swing upon the shaft 10, and inits normal position it holds both of the pawls 18 and 19 out of contactwith the ratchet-wheel 17, and this segment is connected to the core 0'of a solenoid R, and this solenoid is placed in a shunt or branchcircuit to the carbon or in the induced circuit of a series or shunttransformer, and the parts are so proportioned that when the propercurrent is passing to the carbon electrode I the segment 21 will holdboth pawls out of action. If the current is too great, the segment 21will be moved so that one of the pawls will act to raise the carbonelectrode. If the current is insufficient,

the segment 21 will hold that pawl out of action and bring the otherpawl into action, so as to lower the carbon electrode nearer to thehearth E and increase the current passing between the two electrodes.

The segment or dis 1 21 has fastened to it a bar with adj ustablcweights 30, which can be ICS placed so as to vary the weight to be movedby the electromagnet and thus determine the normal current passing tothe electrode.

It is to be understood that a device of the aforesaid character is to beprovided with each electrode, so that the current can be automaticallyregulated as the electrodes are consumed. If desired, there may be acord or chain 22 connected with the upper end of the rack or and passingover a pulley to a weight, so as to partially counterbalance the weightof the electrode.

I claim as my invention- 1. The combination with a hearth having a slabof carbon and forming one electrode, of inclosing walls, a wall androller for supporting one end of the hearth, and an adj ustingscrew forregulating the inclination of the hearth, and carbons adjacent to thehearth forming the other electrode, substantially as set forth.

2. The combination with a hearth having a carbon slab forming oneelectrode, of inclosing brickwork, a range of carbon electrodes abovethe hearth, a hopper surrounding the electrodes and having hollow wallsand pipes through which water is caused to circulate, substantially asset forth.

3. The combination with the hearth forming one electrode, of a range ofcarbon electrodes and means for supporting the same above the hearth, ahopper surrounding the carbon electrodes with one end of the hopperdirectly above the delivery end of the hearth, the end carbon in therange of electrodes being closely adjacent to the hopper so as toprevent material passing down between the carbon electrode and thehopper at the delivery end of the hearth, substantially as set forth.

4. The combination with the hearth having a slab of carbon forming oneelectrode, of a range of carbon electrodes and means for sup porting thesame above the hearth, a hopper around the upper electrodes havingdouble walls and pipes for circulating water within the walls of thehopper, the lower portion of the hopper flaring slightly to prevent thematerial clogging as it passes down to the hearth, substantially as setforth.

5. The combination with the electrodes in an electric furnace, of ahopper for support in g the material and supplying the same between theelectrodes, exterior walls and lines below the sides of the hopper, avertical escape-flue into which the side fiues open, a verticalpartition and deflectors within the vertical escape-flue for arrestingthe solid materials passing off with the gases and doors or flaps at thelower ends of the deflectors for discharging such solid materials,substantially as set forth.

6. The combination in an electric furnace, of stationary walls, a hopperfor containing the material operated upon, a hearth between the wallshaving a surface of carbon, means for supporting the hearth and foradjusting the inclination of the same for the materials acted upon topass off gradually, a chamber into which the materials pass at the endof the hearth, a range of carbon electrodes above and with their endsnear such hearth, and means for adjusting such carbon electrodes,substantially as set forth.

7. The combination with the carbon electrode having a hole drilledtherein and screwthreaded, of a metal plug screwed into such hole, a capscrewed upon the plug and notched, a conductor having a head receivedinto the cap and a clamp for connecting the conductor and cap,substantially as set forth.

8. The combination in an electric furnace, of a hearth forming oneelectrode, a range of carbon electrodes above the hearth, a hoppersurrounding the electrodes and through which the material to be actedupon passes, stirrers and means for actuating the same for loosening thematerial below the hopper and adja cent to the electrodes, substantiallyas set forth.

0. The combination in an electric furnace, of a hearth forming oneelectrode, a range of carbon electrodes above the hearth, ahoppersurrounding the electrodes and through which the material to be actedupon passes, stirrers, an endless chain with which the stirrers areconnected, pulleys around which such chain passes, and means for movingthe chain and stirrers first in one direction and then in the other toloosen the material around the electrodes, substantially as set forth.

Signed by me this 10th day of September, 1896.

EDGAR F. PRICE.

Witnesses:

FREDERICK CHORMANN, A. D. RICHARDS.

